Risk factors for acute surgical site infections after lumbar surgery: a retrospective study

Implications of surgical infection on surgical and hospital outcomes after spine surgery: A NSQIP study of 410,930 patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Surgical infections are unfortunately a fairly common occurrence in spine surgery, with rates reported as high as 16 %. However, there is a relative paucity of studies that look to understand how surgical infections may impact outcome variables. The aim of this study was to assess the impact of surgical infection on other perioperative complications, extended hospital length of stay (LOS), discharge disposition, and unplanned readmission following spine surgery.

METHODS

A retrospective cohort study was performed using the 2016-2022 ACS NSQIP database. Adults receiving spine surgery for trauma, degenerative disease, and tumors were identified using CPT and ICD-9/10 codes. Patients were divided into two cohorts: surgical infection (superficial surgical site infection, deep surgical site infection, organ space surgical site infection, or wound dehiscence) and no surgical infection (those who did not experience any infection). Patient demographics, comorbidities, intraoperative variables, postoperative adverse events (AEs), and healthcare resource utilization were assessed. Multivariate logistic regression analysis was utilized to identify predictors of AEs, extended hospital length of stay, non-routine discharge, and unplanned readmission.

RESULTS

In our cohort of 410,930 patients, 7854 (2.2 %) were found to have experienced a surgical infection. Regarding preoperative variables, a greater proportion of the surgical infection cohort was a female (p < 0.001) and had a higher mean BMI (p < 0.001), greater frailty and ASA scores (p < 0.001), and higher rates of all presenting comorbidities included in the study. Rates of AEs (p < 0.001), unplanned readmission (p < 0.001), reoperation (p < 0.001), non-home discharge (p < 0.001), and 30-day mortality were all greater in the surgical infection group when compared to the group without surgical infection. On multivariate analysis, surgical infection was found to be an independent predictor of experiencing postoperative complications [aOR: 6.15, 95 % CI: (5.72, 6.60), p < 0.001], prolonged LOS [2.71, 95 % CI: (2.54, 2.89), p < 0.001], non-routine discharge [aOR: 1.74, 95 % CI: (1.61, 1.88), p < 0.001], and unplanned readmission [aOR: 22.57, 95 % CI: (21.06, 24.19), p < 0.001].

CONCLUSIONS

Our study found that surgical infection increases the risk of complications, extended LOS, non-routine discharge, and unplanned readmission. Such findings warrant further studies that aim to validate these results and identify risk factors for surgical infections.

Extended Postoperative Antibiotic Prophylaxis Is Associated with No Clinical Value and Higher Projected Cost Following Adult Spinal Surgery: A Stratified Meta-Analysis and Probability-Based Cost Projections

» We aimed to determine the cost-effectiveness of different protocols of extended postoperative antibiotic prophylaxis (E-PAP) following adult spinal surgery.

» Both stratified (randomized controlled trials only) and nonstratified (all studies) analyses demonstrated that E-PAP has no significant value in reducing the rate of surgical site infection (SSI), deep SSI, or superficial SSI.

» Notably, the E-PAP protocols were associated with a significant increase in the length of hospital stay, resulting in an additional expenditure of $244.4 per episode for the E-PAP 72 hours protocol compared with PAP 24 hours and $309.8 per episode for the E-PAP >48 hours protocol compared with PAP <48 hours.

» E-PAP does not demonstrate any significant reduction in the rate of SSIs following spine surgery. However, these extended protocols were significantly associated with an increase in the length of hospital stay and higher overall projected costs.

Is an Elevated Preoperative CRP Level a Predictive Factor for Wound Healing Disorders following Lumbar Spine Surgery?

Postoperative wound infections are a prevalent concern among the hospital-associated infections in Europe, leading to prolonged hospital stays, increased morbidity and mortality, and substantial patient burdens. Addressing the root causes of this complication is crucial, especially given the rising number of spine surgeries due to aging populations.

METHODS

A retrospective analysis was conducted on a cohort of 3019 patients who underwent lumbar spine surgery over a decade in our department. The study aimed to assess the predictors of wound healing disorders, focusing on laboratory values, particularly inflammatory parameters.

RESULTS

Of the 3019 patients, 2.5% (N = 74) experienced deep or superficial wound healing disorders, showing the significant correlation between C-reactive protein (CRP) levels and these disorders (p = 0.004). A multivariate analysis identified several factors, including age, sex, hypertension, diabetes, cardiac comorbidity, surgical duration, dural injury, and blood loss, as being correlated with wound healing disorders.

CONCLUSION

Demographic factors, pre-existing conditions, and perioperative variables play a role in the occurrence of adverse effects related to wound healing disorders. Elevated CRP levels serve as an indicator of increased infection risk, though they are not a definitive diagnostic tool for wound healing disorders.

The Significance of Combined OSTA, HU Value and VBQ Score in Osteoporosis Screening Before Spinal Surgery

OBJECTIVE

This study aimed to assess the utility of a combined assessment using the Osteoporosis Self-Assessment Tool for Asians (OSTA), Hounsfield unit (HU) value, and vertebral bone quality (VBQ) score for preoperative osteoporosis (OP) screening in patients scheduled for spinal surgery.

METHODS

This study encompassed 288 participants, including 128 males and 160 females. Patients were stratified into 2 groups: the OP group (T-score ≤ -2.5) and the non-OP group (T-score > -2.5), determined by dual-energy X-ray absorptiometry (DEXA). Binary logistic regression was used to construct a combined diagnostic model, and the receiver operating characteristic (ROC) curve evaluated the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of these metrics individually or in combination to screen for OP.

RESULTS

Osteoporosis patients exhibited significantly lower OSTA and HU values in comparison to non-OP patients, while their VBQ scores were significantly higher (P < 0.001). The ROC curve analysis results indicated that within the male group, the combined diagnosis had a sensitivity of 93.8%, specificity of 82.3%, accuracy of 85.2%, PPV of 63.8%, and NPV of 97.5%. In the female group, the combined diagnosis had a sensitivity of 93.9%, specificity of 87.4%, accuracy of 90.0%, PPV of 83.6%, and NPV of 95.4%.

CONCLUSIONS

The combined use of OSTA, HU values, and VBQ scores in preoperative OP screening for spinal surgery demonstrates significantly higher accuracy and superior screening value compared to individual assessments. These results establish a robust scientific foundation for conducting preoperative OP screening in patients undergoing spinal surgery.

Development of multidisciplinary, evidenced-based protocol recommendations and implementation strategies for anterior lumbar interbody fusion surgery following a literature review

The anterior lumbar interbody fusion (ALIF) procedure involves several surgical specialties, including general, vascular, and spinal surgery due to its unique approach and anatomy involved. It also carries its own set of complications that differentiate it from posterior lumbar fusion surgeries. The demonstrated benefits of treatment guidelines, such as Enhanced Recovery after Surgery in other surgical procedures, and the lack of current recommendations regarding the anterior approach, underscores the need to develop protocols that specifically address the complexities of ALIF. We aimed to create an evidence-based protocol for pre-, intra-, and postoperative care of ALIF patients and implementation strategies for our health system. A 12-member multidisciplinary workgroup convened to develop an evidence-based treatment protocol for ALIF using a Delphi consensus methodology and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system for rating the quality of evidence and strength of protocol recommendations. The quality of evidence, strength of the recommendation and specific implementation strategies for Methodist Health System for each recommendation were described. The literature search resulted in 295 articles that were included in the development of protocol recommendations. No disagreements remained once the authors reviewed the final GRADE assessment of the quality of evidence and strength of the recommendations. Ultimately, there were 39 protocol recommendations, with 16 appropriate preoperative protocol recommendations (out of 17 proposed), 9 appropriate intraoperative recommendations, and 14 appropriate postoperative recommendations. This novel set of evidence-based recommendations is designed to optimize the patient's ALIF experience from the preoperative to the postoperative period.

Analysis of Postoperative Distal Radius Fracture Outcomes in the Setting of Osteopenia and Osteoporosis for Patients with Comorbid Conditions

Purpose

Distal radius fractures (DRFs) are among the most common orthopedic injuries, especially in the elderly. A wide variety of approaches have been advocated as successful treatment modalities; yet, there remains variability in practice patterns of DRF in patients with osteoporosis and osteopenia. Using large data set analysis, we sought to determine the risk profile of operative fixation of DRF in patients with low bone mineral density.

Methods

A commercially available health care database, PearlDiver, was queried for all patients who underwent open reduction internal fixation of DRFs between 2010 and 2020. The study population was divided into groups based on the presence or absence of osteopenia or osteoporosis and was further classified by patients who were receiving bisphosphonate therapy. Complication rates were calculated, including rates of malunion, surgical site infection, osteomyelitis, hardware failure, and hardware removal. Five-year future fragility fractures were defined in hip, vertebrae, humerus, and wrist fractures. Chi-square analysis and logistic regression were performed to determine an association between these comorbidities and various postoperative complications.

Results

A total of 152,926 patients underwent open reduction internal fixation of a DRF during the study period. Chi-square analysis of major complications at 3 months showed a statistically significant increase in malunion in patients with osteopenia (P = .05) and patients with osteoporosis (P = .05) who underwent open reduction internal fixation. Logistic regression analysis at 12 months after surgery demonstrated that osteopenia was associated with an increased risk of hardware failure (P < .0001), hardware removal (P < .0001), surgical site infection (P < .0001), and malunion (P = .004). Osteoporosis was associated with a significantly increased risk of hardware failure (P = .01), surgical site infection (P < .0001), and malunion (P < .0001).

Conclusions

We demonstrated, using large data set analysis, that DRF patients with osteopenia and osteoporosis are predicted to be at increased risk of multiple postoperative complications, and thus, bone density should be strongly considered in treatment planning for these patients.

Type of study/level of evidence

Prognostic III.

MRI-Based Score for Assessment of Bone Mineral Density in Operative Spine Patients

STUDY DESIGN

Retrospective comparison.

OBJECTIVE

The aim was to determine whether a previously developed magnetic resonance imaging (MRI)-derived bone mineral density (BMD) scoring system can differentiate between healthy and osteoporotic vertebrae and to validate this scoring system against quantitative computed tomography measurements.

SUMMARY OF BACKGROUND DATA

BMD is an important preoperative consideration in spine surgery. Techniques to measure BMD are subject to falsely elevated values in the setting of spondylosis (dual-energy X-ray absorptiometry) or require significant exposure to radiation [quantitative computed tomography (QCT)]. Previous studies have shown that MRI may be utilized to measure bone quality using changes in the bone marrow signal observed on T1-weighted MRIs.

MATERIALS AND METHODS

Retrospective study of patients who underwent operative lumbar procedures at a single tertiary institution between 2016 and 2021 (n=61). Vertebral bone quality (VBQ) scores were measured by dividing the median signal intensities of L1-L4 by the signal intensity of cerebrospinal fluid on noncontrast T1W MRI. Demographic data, comorbidities, VBQ scores, and QCT-derived T scores and BMD of the lumbar spine were compared between healthy ( T score ≥-1; n=21), osteopenic (-2.5 < T score < -1; n=21), and osteoporotic ( T score ≤-2.5; n=19) cohorts using analysis of variance with post hoc Tukey test. Linear regression and receiver operating characteristic curve analyses were performed to assess the predictive value of VBQ scores. Pearson correlation test was used to evaluate the association between VBQ scores and QCT-derived measurements.

RESULTS

VBQ differentiated between healthy and osteoporotic groups ( P =0.009). Receiver operating characteristic curve analysis revealed that a greater VBQ score was associated with presence of osteoporosis (area under the curve=0.754, P =0.006). Cutoff VBQ for osteoporosis was 2.6 (Youden index 0.484; sensitivity: 58%; specificity: 90%). VBQ scores weakly correlated with QCT-derived BMD ( P =0.03, r =-0.27) and T scores ( P =0.04, r =-0.26).

CONCLUSION

This study attempted to further validate a previously developed MRI-based BMD scoring system against QCT-derived measurements. VBQ score was found to be a significant predictor of osteoporosis and could differentiate between healthy and osteoporotic vertebrae.

Hypoalbuminemia and Elevated CRP are Risk Factors for Deep Infections and Urinary Tract Infections After Lumbar Spine Surgery in a Large Retrospective Patient Population

STUDY DESIGN

Retrospective cross-sectional study.

OBJECTIVES

To determine if pre-operative albumin and CRP can predict post-operative infections after lumbar surgery.

METHODS

Patients who underwent an anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), or lumbar discectomy were identified using a patient record database (PearlDiver) and were included in this retrospective study. Patients were stratified by Charlson Comorbidity Index (CCI) scores and pre-operative albumin and CRP status. Post-operative complications included deep infections and urinary tract infections within 3 months of the surgery and revisions within 1 year of the surgery.

RESULTS

74,280 patients were included in this study. 21,903 had pre-operative albumin or CRP lab values. 7,191 (33%), 12,183 (56%), and 2,529 (12%) patients underwent an ALIF, PLIF, and a lumbar discectomy, respectively. 16,191 did not have any complication (74%). The most common complication was UTI (16%). Among all patients, hypoalbuminemia was a significant risk factor for deep infection and UTI after ALIF, deep infection, UTI, and surgical revision after PLIF, and deep infection after lumbar discectomy. Elevated CRP was a significant risk factor for deep infection after ALIF, UTI after PLIF, and deep infection after lumbar discectomy in patients with a CCI ≤ 3.

CONCLUSIONS

Pre-operative hypoalbuminemia and elevated CRP were significant risk factors for deep infection, UTI, and/or revision, after ALIF, PLIT, and/or lumbar discectomy. Future studies with a larger population of patients with low albumin and high CRP values are needed to further elaborate on the current findings.

Understanding risk factors and microbial trends implicated in the development of Whipple-related surgical-site infections

Objective

The purpose of this study is to understand the role of risk factors and postoperative complications seen in patients undergoing Whipple procedures in the development of surgical site infections. Our secondary goal was to evaluate whether microbial patterns differed between preoperative antibiotic classes, offering insight into the effectiveness of current practices while promoting antibiotic stewardship.

Design

We performed a retrospective cohort study comparing patients with and without SSIs.

Setting

This study was conducted at a tertiary-care center in the southeastern United States.

Participants

Patients who underwent a Whipple procedure between 2012 and 2021 were acquired from the National Surgical Quality Improvement Program (NSQIP) database.

Results

Patients with a bleeding disorder reported higher SSI rates (P = .04), whereas patients with a biliary stent reported lower surgical site infection (SSI) rates (P = .02) Those with postoperative complications had higher SSI rates, including delayed gastric emptying (P < .001) and pancreatic fistula (P < .001). Patients with longer operative times were 1.002 times more likely to develop SSIs (adjusted odds ratio [aOR], 1.002; 95% confidence interval [CI], 1.001-1.004; P = .006) whereas surgical indications for malignancy correlated with decreased SSIs risk (aOR, 0.578; 95% CI, 0.386-866) when adjusting for body mass index, surgical indication, and duration of surgical procedure.

Conclusions

Optimizing preoperative management of modifiable risk factors for patients undergoing pancreatoduodenectomies and decreasing operative times may reduce SSI rates and patient and hospital burden. Further research is needed to understand whether stent placement reduces SSI risk in pancreatoduodenectomy.

Risk Factors for Infection and Revision Surgery following Patellar Tendon and Quadriceps Tendon Repairs: An Analysis of 3,442 Patients

Disruption of the extensor mechanism is debilitating with surgical repair being the accepted treatment. The incidence of infection and reoperation after extensor mechanism repair are not well reported in the literature. Thus, the objective of the current study was to (1) determine the incidence of surgical site infection and reoperation within 1 year of primary extensor mechanism repair and (2) identify independent risk factors for infection and reoperation following patellar and quadriceps tendon repair. A retrospective review of the 100% Medicare Standard Analytic files from 2005 to 2014 was performed to identify patients undergoing isolated patellar tendon repair and quadriceps tendon repair. Diagnosis of infection within 1 year of operative intervention and revision repair were assessed. Extensor mechanism injuries in the setting of total knee arthroplasty and polytrauma were excluded. Multivariate logistic regression analysis was performed to evaluate risk factors for postoperative infection and reoperation within 1 year. Infection occurred in 6.3% of patients undergoing patellar tendon repair and 2.6% of patients undergoing quadriceps tendon repair. Diabetes mellitus (odds ratio [OR] = 1.89, p = 0.005) was found to be an independent risk factor for infection following patellar tendon repair. Reoperation within 1 year occurred in 1.3 and 3.9% following patellar tendon and quadriceps tendon repair, respectively. Age less than 65 years (OR = 2.77, p = 0.024) and obesity (OR = 3.66, p = 0.046) were significant risk factors for reoperation after patellar tendon repair. Hypertension (OR = 2.13, p = 0.034), hypothyroidism (OR = 2.01, p = 0.010), and depression (OR = 2.41, p = 0.005) were significant risk factors for reoperation after quadriceps tendon repair. Diabetes mellitus was identified as a risk factor for infection after patellar tendon repair. Age less than 65 years, peripheral vascular disease, and congestive heart failure were risk factors for infection after quadriceps tendon repair. The current findings can be utilized to counsel patients regarding preoperative risk factors for postoperative complications prior to surgical intervention for extensor mechanism injuries.

Osteopenia and Sarcopenia as Potential Risk Factors for Surgical Site Infection after Posterior Lumbar Fusion: A Retrospective Study

Surgical site infection (SSI) is a feared complication in spinal surgery, that leads to lower outcomes and increased healthcare costs. Among its risk factors, sarcopenia and osteopenia have recently attracted particular interest. The purpose of this article is to evaluate the influence of sarcopenia and osteopenia on the postoperative infection rate in patients treated with posterior fusion for degenerative diseases of the lumbar spine. This retrospective study included data from 308 patients. Charts were reviewed and central sarcopenia and osteopenia were evaluated through magnetic resonance images (MRI), measuring the psoas to lumbar vertebral index (PLVI) and the M score. Multivariate linear regression was performed to identify independent risk factors for infection. The postoperative SSI rate was 8.4%. Patients with low PLVI scores were not more likely to experience postoperative SSI (p = 0.68), while low M-score patients were at higher risk of developing SSI (p = 0.04). However, they did not generally show low PLVI values (p = 0.5) and were homogeneously distributed between low and high PLVI (p = 0.6). Multivariate analysis confirmed a low M score to be an independent risk factor for SSI (p = 0.01). Our results suggest that osteopenia could have significant impact on spinal surgery, and prospective studies are needed to better investigate its role.

Closed-suction drainage in thoracolumbar spinal surgery-clinical routine without evidence? a systematic review

PURPOSE

The considered benefit of surgical drain use after spinal surgery is to prevent local accumulation of a haematoma by decompressing the closed space in the approach of the surgical site. In this context, the aim of the present systematic review was to prove the benefit of the routine use of closed-suction drains.

METHODS

We conducted a comprehensive systematic review of the literature according to the Preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist and algorithm.

RESULTS

Following the literature search, 401 potentially eligible investigations were identified. Eventually, a total of 24 studies with 8579 participants were included. Negative suction drainage led to a significantly higher volume of drainage fluid. Drainage duration longer than 72 h may be associated with a higher incidence of Surgical side infections (SSI); however, accompanying antibiotic treatment is unnecessary. Regarding postoperative haematoma and neurological complications, no evidence exists concerning their prevention. Hospital stay length and related costs may be elevated in patients with drainage but appear to depend on surgery type.

CONCLUSIONS

With regard to the existing literature, the use of closed-suction drainage in elective thoracolumbar spinal surgery is not associated with any proven benefit for patients and cannot decrease postoperative complications.

Risk factors for surgical site infection following spinal surgery: A meta-analysis

STUDY DESIGN

A meta-analysis.

BACKGROUND

We performed a meta-analysis to explore risk factors of surgical site infection (SSI) following spinal surgery.

METHODS

An extensive search of literature was performed in English database of PubMed, Embase, and Cochrane Library and Chinese database of CNKI and WANFANG (up to October 2020). We collected factors including demographic data and surgical factor. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

RESULTS

Totally, 26 studies were included in the final analysis. In our study, the rate of SSI after spinal surgery was 2.9% (1222 of 41,624). Our data also showed that fusion approach (anterior vs posterior; anterior vs combined), osteotomy, transfusion, a history of diabetes and surgery, hypertension, surgical location (cervical vs thoracic; lumbar vs thoracic), osteoporosis and the number of fusion levels were associated with SSI after spinal surgery. However, age, sex, a history of smoking, body mass index, fusion approach (posterior vs combined), surgical location (cervical vs lumbar), duration of surgery, blood loss, using steroid, dural tear and albumin were not associated with development of SSI.

CONCLUSIONS

In our study, many factors were associated with increased risk of SSI after spinal surgery. We hope this article can provide a reference for spinal surgeons to prevent SSI after spinal surgery.

Diabetes Mellitus Is Not a Negative Prognostic Factor for Patients Undergoing Hip Arthroscopy

Diabetes mellitus (DM) has been associated with inferior clinical outcomes and comorbidities in general. The authors sought to compare the outcomes of hip arthroscopy at minimum 2-year follow-up for patients with DM with those of patients without DM. Data were prospectively collected and retrospectively reviewed for patients who underwent hip arthroscopy between February 2008 and December 2014. The inclusion criteria were patients with DM who underwent hip arthroscopy for the treatment of femoroacetabular impingement and labral tears and had preoperative patient- reported outcomes. The exclusion criteria were preoperative Tönnis grade greater than 1, previous ipsilateral hip surgery, and/or previous conditions. All patients with DM were matched in a 1:2 ratio to control patients without DM. The matching criteria were age at surgery, sex, body mass index, workers' compensation, capsular treatment, and acetabular Outerbridge grade 0 or 1 vs 2, 3, or 4. Of 29 eligible patients with DM, 26 (89.7%) had minimum 2-year follow-up. Twenty-six patients with DM were matched and compared with 52 patients without DM. Acetabuloplasty was performed more frequently in the control group (P=.01). There were no other statistically significant differences detected in terms of demographics, preoperative radiographic imaging, intraoperative findings, procedures, preoperative scores, follow-up scores, revision rates, rates of conversion to total hip arthroplasty, or complication rates. Patients with DM demonstrated favorable improvements at 2 or more years after arthroscopic labral treatment when compared with a matched control group without DM. The DM group demonstrated a non-statistically significant trend toward inferior outcomes in all patient-reported outcomes, visual analog scale score, and satisfaction. [Orthopedics. 2021;44(4):241-248.].

Consensus statement for perioperative care in lumbar spinal fusion: Enhanced Recovery After Surgery (ERAS®) Society recommendations

BACKGROUND

Enhanced Recovery After Surgery (ERAS) evidence-based protocols for perioperative care have led to improvements in outcomes in numerous surgical areas, through multimodal optimization of patient pathway, reduction of complications, improved patient experience and reduction in the length of stay. ERAS represent a relatively new paradigm in spine surgery.

PURPOSE

This multidisciplinary consensus review summarizes the literature and proposes recommendations for the perioperative care of patients undergoing lumbar fusion surgery with an ERAS program.

STUDY DESIGN

This is a review article.

METHODS

Under the impetus of the ERAS® society, a multidisciplinary guideline development group was constituted by bringing together international experts involved in the practice of ERAS and spine surgery. This group identified 22 ERAS items for lumbar fusion. A systematic search in the English language was performed in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials. Systematic reviews, randomized controlled trials, and cohort studies were included, and the evidence was graded according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. Consensus recommendation was reached by the group after a critical appraisal of the literature.

RESULTS

Two hundred fifty-six articles were included to develop the consensus statements for 22 ERAS items; one ERAS item (prehabilitation) was excluded from the final summary due to very poor quality and conflicting evidence in lumbar spinal fusion. From these remaining 21 ERAS items, 28 recommendations were included. All recommendations on ERAS protocol items are based on the best available evidence. These included nine preoperative, eleven intraoperative, and six postoperative recommendations. They span topics from preoperative patient education and nutritional evaluation, intraoperative anesthetic and surgical techniques, and postoperative multimodal analgesic strategies. The level of evidence for the use of each recommendation is presented.

CONCLUSION

Based on the best evidence available for each ERAS item within the multidisciplinary perioperative care pathways, the ERAS® Society presents this comprehensive consensus review for perioperative care in lumbar fusion.

Web-Based Calculator Predicts Surgical-Site Infection After Thoracolumbar Spine Surgery

BACKGROUND

Surgical-site infection (SSI) after spine surgery leads to increased length of stay, reoperation, and worse patient quality of life. We sought to develop a web-based calculator that computes an individual's risk of a wound infection following thoracolumbar spine surgery.

METHODS

We performed a retrospective review of consecutive patients undergoing elective degenerative thoracolumbar spine surgery at a tertiary-care institution between January 2016 and December 2018. Patients who developed SSI requiring reoperation were identified. Regression analysis was performed and model performance was assessed using receiver operating curve analysis to derive an area under the curve. Bootstrapping was performed to check for overfitting, and a Hosmer-Lemeshow test was employed to evaluate goodness-of-fit and model calibration.

RESULTS

In total, 1259 patients were identified; 73% were index operations. The overall infection rate was 2.7%, and significant predictors of SSI included female sex (odds ratio [OR] 3.0), greater body mass index (OR 1.1), active smoking (OR 2.8), worse American Society of Anesthesiologists physical status (OR 2.1), and greater surgical invasiveness (OR 1.1). The prediction model had an optimism-corrected area under the curve of 0.81. A web-based calculator was created: https://jhuspine2.shinyapps.io/Wound_Infection_Calculator/.

CONCLUSIONS

In this pilot study, we developed a model and simple web-based calculator to predict a patient's individualized risk of SSI after thoracolumbar spine surgery. This tool has a predictive accuracy of 83%. Through further multi-institutional validation studies, this tool has the potential to alert both patients and providers of an individual's SSI risk to improve informed consent, mitigate risk factors, and ultimately drive down rates of SSIs.

Complex wound closure by plastic surgery following resection of spinal neoplasms minimizes postoperative wound complications in high-risk patients

OBJECTIVE

Wound breakdown and infection are common postoperative complications following resection of spinal neoplasms. Accordingly, it has become common practice at some centers for plastic surgeons to assist with closure of large posterior defects after spine tumor resection. In this study, the authors tested the hypothesis that plastic surgery closure of complex spinal defects improves wound outcomes following resection of spinal neoplastic disease.

METHODS

Electronic medical records of consecutive patients who underwent resection of a spinal neoplasm between June 2015 and January 2019 were retrospectively reviewed. Patients were separated into two subpopulations based on whether the surgical wound was closed by plastic surgery or neurosurgery. Patient demographics, preoperative risk factors, surgical details, and postoperative outcomes were collected in a central database and summarized using descriptive statistics. Outcomes of interest included rates of wound complication, reoperation, and mortality. Known preoperative risk factors for wound complication in spinal oncology were identified based on literature review and grouped categorically. The presence of each category of risk factors was then compared between groups. Univariate and multivariate linear regressions were applied to define associations between individual risk factors and wound complications.

RESULTS

One hundred six patients met inclusion criteria, including 60 wounds primarily closed by plastic surgery and 46 by neurosurgery. The plastic surgery population included more patients with systemic metastases (58% vs 37%, p = 0.029), prior radiation (53% vs 17%, p < 0.001), prior chemotherapy (37% vs 15%, p = 0.014), and sacral region tumors (25% vs 7%, p = 0.012), and more patients who underwent procedures requiring larger incisions (7.2 ± 3.6 vs 4.5 ± 2.6 levels, p < 0.001), prolonged operative time (413 ± 161 vs 301 ± 181 minutes, p = 0.001), and greater blood loss (906 ± 1106 vs 283 ± 373 ml, p < 0.001). The average number of risk factor categories present was significantly greater in the plastic surgery group (2.57 vs 1.74, p < 0.001). Despite the higher relative risk, the plastic surgery group did not experience a significantly higher rate of wound complication (28% vs 17%, p = 0.145), reoperation (17% vs 9%, p = 0.234), or all-cause mortality (30% vs 13%, p = 0.076). One patient died from wound-related complications in each group (p = 0.851). Regression analyses identified diabetes, multilevel instrumentation, and BMI as the factors associated with the greatest wound complications.

CONCLUSIONS

Involving plastic surgery in the closure of spinal wounds after resection of neoplasms may ameliorate expected increases in wound complications among higher-risk patients.

Chronic Opioid Use Is Associated With Surgical Site Infection After Lumbar Fusion

STUDY DESIGN

Retrospective, database review.

OBJECTIVE

The purpose of this study was to explore the association between preoperative opioid use and postoperative infection requiring operative wound washout in elective lumbar fusion patients.

SUMMARY OF BACKGROUND DATA

Numerous peer-reviewed publications have conducted multivariate analyses of risk factors for surgical site infection. However, few have explored preoperative opioid use. Opioids have been widely prescribed preoperatively for pain management, but their effect on postsurgical infection is currently inconclusive.

METHODS

We retrospectively queried the PearlDiver national insurance claims database and included patients from 2007 to 2017 with a history of lumbar fusion. Any interbody fusion history designated exclusion. We stratified patients by single or multilevel procedures and conducted univariate analyses of previously documented infection risk factors, as well as our variable of interest, chronic preoperative opioid use. Variables associated (P < 0.100) with the outcome measure of 90-day postoperative infection treated with operative irrigation and wound debridement were included in a multivariate analysis.

RESULTS

A total of 12,519 patients matched our inclusion criteria. Among the single-level cohort, only diabetes was observed to be associated with infection requiring operative wound washout and thus no subsequent regression was performed. For the cohort of patients who underwent multilevel fusion, chronic opioid use, diabetes, congestive heart failure, chronic obstructive pulmonary disease, and hypertension trended toward significance in the univariate analysis and were included in a logistic regression model. In the multivariate analysis, chronic opioid use (odds ratio [OR] = 1.435, P = 0.025), diabetes (OR = 1.591 P = 0.003), and congestive heart failure (OR = 1.929, P = 0.003) were identified as independent risk factors for infection requiring operative wound washout.

CONCLUSION

In this analysis, preoperative opioid use was significantly associated with infection requiring operative wound washout in multilevel lumbar fusion patients. Limiting opioid consumption may have the benefit of reducing the risk of infection following spine surgery.

LEVEL OF EVIDENCE

3.

Prophylactic postoperative measures to minimize surgical site infections in spine surgery: systematic review and evidence summary

BACKGROUND CONTEXT

There are three phases in prophylaxis of surgical site infections (SSI): preoperative, intraoperative and postoperative. There is lack of consensus and paucity of evidence with SSI prophylaxis in the postoperative period.

PURPOSE

To systematically evaluate the literature, and provide evidence-based summaries on postoperative measures for SSI prophylaxis in spine surgery.

STUDY DESIGN

Systematic review, meta-analysis, evidence synthesis.

METHODS

A systematic review conforming to PRIMSA guidelines was performed utilizing PubMed (MEDLINE), EMBASE, and the Cochrane Database from inception to January 2019. The GRADE approach was used for quality appraisal and synthesis of evidence. Six postoperative care domains with associated key questions were identified. Included studies were extracted into evidence tables, data synthesized quantitatively and qualitatively, and evidence appraised per GRADE approach.

RESULTS

Forty-one studies (nine RCT, 32 cohort studies) were included. In the setting of preincisional antimicrobial prophylaxis (AMP) administration, use of postoperative AMP for SSI reduction has not been found to reduce rate of SSI in lumbosacral spine surgery. Prolonged administration of AMP for more than 48 hours postoperatively does not seem to reduce the rate of SSI in decompression-only or lumbar spine fusion surgery. Utilization of wound drainage systems in lumbosacral spine and adolescent idiopathic scoliosis corrective surgery does not seem to alter the overall rate of SSI in spine surgery. Concomitant administration of AMP in the presence of a wound drain does not seem to reduce the overall rate of SSI, deep SSI, or superficial SSI in thoracolumbar fusion performed for degenerative and deformity spine pathologies, and in adolescent idiopathic scoliosis corrective surgery. Enhanced-recovery after surgery clinical pathways and infection-specific protocols do not seem to reduce rate of SSI in spine surgery. Insufficient evidence exists for other types of spine surgery not mentioned above, and also for non-AMP pharmacological measures, dressing type and duration, suture and staple management, and postoperative nutrition for SSI prophylaxis in spine surgery.

CONCLUSIONS

Despite the postoperative period being key in SSI prophylaxis, the literature is sparse and without consensus on optimum postoperative care for SSI prevention in spine surgery. The current best evidence is presented with its limitations. High quality studies addressing high risk cohorts such as the elderly, obese, and diabetic populations, and for traumatic and oncological indications are urgently required.

Difficulties in Treating Postirradiation Kyphosis in Adults: A Series of Five Cases

STUDY DESIGN

Clinical case series.

OBJECTIVE

To assess objective outcomes of surgical correction of post-external beam radiation therapy (ERBT) kyphosis in a series of five adults.

SUMMARY OF BACKGROUND DATA

EBRT is a well-established treatment for many cancers in children and adults. One complication associated with EBRT is postirradiation spine deformity. Scoliosis is the most common deformity, but kyphosis also occurs frequently. Differences in deformity patterns are likely related to the location and intensity of radiation. To our knowledge, no studies have addressed treatment of these deformities in adults, and the most recent case series (of children) was published in 2005.

METHODS

We present a series of five adults who underwent surgery for postirradiation kyphosis, with a mean follow-up of 3.8 years (range, 2.5-6.2 years).

RESULTS

Surgery improved the kyphotic deformity in all patients. Overall mean kyphotic deformity correction was 56° and was larger for cervical/cervicothoracic deformities (mean, 76°) than for lumbar deformities (mean, 42°) at midterm follow-up. Patients reported significant improvements in pain and self-image. Consistent with prior case series of children, we observed a high rate of complications (mean, 1.4 complications per patient) in adults. Three patients each underwent an unplanned surgical procedure because of a complication.

CONCLUSION

The surgical treatment of postirradiation kyphotic spinal deformity is challenging, with common postoperative complications such as infection, instrumentation failure, and pseudarthrosis. However, with modern surgical techniques and spinal instrumentation, excellent deformity correction can be achieved and maintained. We recommend performing a two-stage procedure for cervicothoracic deformity, with anterior release followed by posterior fusion and instrumentation. In thoracolumbar deformities, correction can be achieved through single-stage posterior fusion. Rigid spinopelvic fixation with sacral-alar-iliac screws and second-stage anterior lumbar interbody fusion at L5-S1 is recommended to reduce nonunion risk. Cement augmentation of proximal and distal anchors can help prevent junctional failure.

LEVEL OF EVIDENCE

Level IV.

The impact of type 2 diabetes on bone metabolism and growth after spinal fusion

BACKGROUND CONTEXT

Some clinical reports suggest diabetes may have a negative effect on spinal fusion outcomes, although no conclusive experimental research has been conducted to investigate the causality, impact, and inherent risks of this growing patient population.

PURPOSE

To analyze the hypothesis that type 2 diabetes (T2DM) inhibits the formation of a solid bony union after spinal fusion surgery by altering the local microenvironment at the fusion site through a reduction in growth factors critical for bone formation.

STUDY DESIGN/SETTING

In vivo rodent model of type 2 diabetes.

METHODS

Twenty control (Sprague Dawley, SD) and 30 diabetic (Zucker Diabetic Sprague Dawley, ZDSD) rats underwent posterolateral and laminar fusion surgery using a tailbone autograft implanted onto the L4/L5 transverse processes. A subset of animals was sacrificed 1-week postsurgery for growth factor analysis. Remaining rats were sacrificed 3-month postsurgery for fusion evaluation via manual palpation, micro-CT, and histology.

RESULTS

There was no significant difference in the manual palpation fusion rate between ZDSD rats and SD control rats. Growth factor assay of fusion site explants at early sacrifice demonstrated PDGF was upregulated in the ZDSD rats. TGFB, IGF, and VEGF were not statistically different between groups. Bone mineral density as determined by micro-CT was significantly lower in ZDSD rats compared to SD controls and was a significant function of HbA1c.

CONCLUSIONS

Data generated in this in vivo rat model of T2DM demonstrate that the metabolic dysregulation associated with the diabetic condition negatively impacts the quality and density of the formed fusion mass. Increased measures of diabetic status, as determined by blood glucose and HbA1c, were correlated with decreased quality of formed fusion, highlighting the importance of diabetic status monitoring and regulation to bone health, particularly during bone healing.

CLINICAL RELEVANCE

T2DM rats demonstrated increased rates of infection, metabolic dysregulation, and a reduction in spinal fusion consolidation. Clinicians should consider these negative effects during preoperative care and treatment of this growing patient population.

Multivariate analysis of incision infection after posterior lumbar surgery in diabetic patients: A single-center retrospective analysis

BACKGROUND

Patients requiring posterior lumbar surgery have increased annually. Incision infection after lumbar surgery has serious consequences for patients. However, data on the related factors of incision infection after lumbar surgery in diabetic patients are limited. Therefore, this study aimed to analyze diabetic patients who underwent lumbar surgery and to explore the risk factors of perioperative incision infection to provide a scientific basis for perioperative intervention of lumbar spine surgery and reduce risk of incision infection in such patients.

METHODS

We retrospectively reviewed data of diabetic patients who underwent posterior lumbar surgery from 2011 to 2016. A total of 523 diabetic patients undergoing posterior lumbar surgery were analyzed for the influence of various risk factors on postoperative incision infection. Univariate and multivariate logistic regression was performed. The test level was α=.05, and P < .05 was considered statistically significant.

RESULTS

In the past 6 years, among the 523 diabetic patients, the incidence of incision infection after posterior lumbar surgery was approximately 7.1%, of which the shallow incision infection rate was 4.2% and the deep incision infection rate was 2.9%. Incision infection of posterior lumbar surgery in diabetic patients is related to smoking, preoperative glycosylated hemoglobin A1c, postoperative albumin (Alb), surgical segment, operation time, and intraoperative blood loss, especially on postoperative fasting blood glucose, postoperative postprandial blood glucose, local subcutaneous fat thickness, and operation sequence (odds ratio >5.00). Meanwhile, sex, age, body mass index (BMI), preoperative Alb, and newly diagnosed diabetes were not highly correlated with incision infection after posterior lumbar surgery.

CONCLUSION

Local subcutaneous fat thickness is a better indicator for predicting incision infection compared with BMI. In diabetic patients undergoing lumbar surgery, actively controlling blood glucose fluctuations, restoring normal diet early after surgery, and optimizing surgical procedures to reduce trauma and operative time can effectively reduce the risk of infection after posterior lumbar surgery.

Impact of assessment of bone status before corrective surgery of lumbar spine in patients over 50 years old

Background and objective: There is absence of data on the prevalence of osteoporosis before corrective surgery of the lumbar spine. We do not know the impact of bone assessment before corrective spine surgery, regarding the prevalence of osteoporosis, risk factors for osteoporosis, and prescription of osteoporotic treatment. Our objective was to evaluate the impact of assessment of bone status before corrective surgery of the lumbar spine.

Methods: This retrospective study was conducted over a period of 30 months. Patients included were over 50 years old and had been referred to rheumatology consultation prior to corrective surgery of the lumbar spine with osteosynthesis, for scoliosis or spondylolisthesis. Assessment of bone status consisted in looking for risk factors for osteoporotic fracture, performing bone densitometry with the calculation of TBS (trabecular bone score) and the possible introduction of treatment for osteoporosis. Data were collected on complications related to bone fragility during follow-up.

Results: Twenty-eight patients with a median age of 71.2 years (55.5–84.8) were included; 89% were women. T score was <−2.5 in 14.3% (4/28) and −1 to −2.5 in 42.9% (12/28) on at least one of the three sites analyzed. Fifty percent of patients had a TBS <1.2, a history of more than four falls per year, a duration of more than 20 s in the Timed Up and Go Test, and/or sedation treatment. Vitamin-calcium supplementation and treatment for osteoporosis were prescribed in 71.4% and 17.8% of cases, respectively. During follow-up, 3 patients had one or more osteoporotic vertebral fractures and 4 patients had loosening of implanted devices.

Conclusion: Despite a low prevalence of densitometric osteoporosis and therapeutic management, one in four patients had a bone complication, suggesting the superiority of TBS as an indicator of bone status.

Risk factors for surgical site infection following lumbar spinal surgery: a meta-analysis

Objective

To identify risk factors for surgical site infection (SSI) in patients who had undergone lumbar spinal surgery.

Methods

Studies published in PubMed, Web of Science, and Embase were systematically reviewed to determine risk factors for SSI following lumbar spinal surgery. Results are expressed as risk ratios (RRs) with 95% CIs and weighted mean difference (WMD) with 95% CI. A fixed-effect or random-effect model was used to pool the estimates according to heterogeneity among the studies included.

Results

Sixteen studies involving 13,393 patients were included in this meta-analysis. Pooled estimates suggested that diabetes (RR 2.19, 95% CI 1.43–3.36; P<0.001), obesity (RR 2.87, 95% CI 1.62–5.09; P<0.001), BMI (WMD 1.32 kg/m², 95% CI 0.39–2.25; P=0.006), prolonged operating time (WMD 24.96 minutes, 95% CI 14.77–35.15; P<0.001), prolonged hospital stay (WMD 2.07 days, 95% CI 0.28–3.87; P=0.024), hypertension (RR 1.28, 95% CI 1.08–1.52; P=0.005), and previous surgery (RR 2.06, 95% CI 1.39–3.06; P<0.001) were independent risk factors for SSI in patients who had undergone lumbar spine surgery. Current smoking (RR 0.89, 95% CI 0.75–1.06; P=0.178), American Society of Anesthesiologists grade >2 (RR 2.63, 95% CI 0.84–8.27; P=0.098), increased age (WMD 1.43 years, 95% CI −1.15 to 4.02; P=0.278), COPD (RR 1.21, 95% CI 0.68–2.17; P=0.521), cardiovascular disease (RR 1.63, 95% CI 0.40–6.70; P=0.495), rheumatoid arthritis (RR 1.76, 95% CI 0.53–5.90; P=0.359), and osteoporosis (RR 1.91, 95% CI 0.79–4.63; P=0.152) were not risk factors for postoperative SSI.

Conclusion

Our results identified several important factors that increased the risk of postoperative SSI. Knowing these risk factors, surgeons could adequately analyze and evaluate risk factors in patients and then develop prevention measurements to reduce the rate of SSI.